Carriage-wheel



(No Model.)

S. D. FORBES.

CARRIAGE WHEEL.

N0. 378,302. Patented Feb. 21, 1888..

Iinrrnn "rnrns PATE'r SAMUEL D. FORBES, OF WILMINGTON, DELAWARE.

CARRIAGE-WHEEL.

SPECIFICATION forming part of Letters Patent No. 378,302, dated February 21, 1888. Application filed November 4, 1S 87. Serial Ila 254.292. (No model.)

To aZZ whom it may concern:

Be it known that I, SAMUEL D. Forrsns, a citizen of the United States, residing at W'ilmington, in the county of New Castle and State of Delaware, have invented certain new and useful Improvements in Oarriage-lVheels; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appcrtains to make and use the same.

This invention relates to spokes and fellies for carriage-wheels; and its object is, first, to increase the strength of both the folly and the spoke-tench without increasing the size of the folly and without requiring a larger piece of timber to make the spoke; second, to make a lighter wheel of equal strength or a stronger wheel of equal weight; and, third, to give a more graceful form to the spokes and the wheel.

To this end my invention consists, first, in a felly having elongated niortises and spokes having tenons broad in the direction of. the plane of the wheel to fit the said mortises; and, second, in reel-shaped spokes, as hereinafter described and claimed, reference being had to the accompanying drawings, in which Figures I, II, III, and IV represent the outer ends of common spokes as seen looking upon the circumference of the wheel. Figs. V, VI, VII, and VIII represent the outer ends of spokes, showing different modifications of my invention. Figs. IX, X, XI, and XII represent side elevations of the outer ends of the spokes shown in the previous four figures, the folly being represented in longitudinal vertical section. Fig. XIII represents a spoke of usual form, excepting the outer tenon, which is in accordance with my invention; and Fig-XIV represents a spoke formed throughout according to my invention.

The usual method of making the joint of the Telly and a spoke in a wheel is to bore a round hole radially through the folly and to form a cylindrical radial tenon on the spoke to fit the said hole closely, as shown in Fig. I, in which (t represents the folly, Z) the tenon, and the dotted circumference c the shoulder of the spoke at the base of the tencn. Such tencns are usually split transversely to receive a wedge, d, to force the tenon against the ends of the grain of the felly; but it is evident on inspection that the semicircular form of each half of the tenon will act asa wedge to part or split the folly if too much force be applied to the Wedge d. To obviatethis tendency, and at the same time to do away with the wedge, it is common to bore a round hole (see dotted line 9, Fig. II)-say, for example, five eighths of an inch in diameter-through the felly, then to form a cylindrical tenon larger than this hole-- say eleven-sixteenths of an inch in diameterby means of the common hollow auger, and afterward to file off the front and rear faces of the tenon, reducing it to a less diameter than the hole transversely to the folly, and to drive the felly upon the spoke-tenon thus oval shaped. (See Fig. II.) If the face-filing has been done with skill and judgment, a tenon may be so driven as to materially compact the grain of the wood in both tenon and felly without splitting the latter. The felly being now under all the tension it will bear, a very little turning of the spoke-tcnon in its socket will split the folly, and this oval tenon is particularly adapted to serve as a splitting wedge or cam when revolved by the twisting of the spoke that occurs whenever the light rim is bent out of its plane at any point. Every time a wheel slips sidewise from a cobblestone or is strained by striking a car-track obliquely the tendency is to twist the spokes in their bearings and to split the folly.

Before the advent of special machinery for wheel-makingit was commonto form by handtools square mortises and tcnons, as shown in Fig. III, and these might be somewhat elongated by driving wedges, as in Fig. IV. flhe usual proportion of round tenons is a fiveeighths-inch tenon to an inch-wide felly, leav ing but three-sixteenths oi an inch of the folly at each side of the tenon. 'Io obviate this source of weakness, I make the spoke-tenon broad in the direction of the plane of the wheel 9 and narrow or thin transversely thereto, or relatively to the width of the felly, as shown in different modifications in the drawings after Fig. IV.

Fig. V may be compared with Fig. I to old cylindrical tenon.

show the proportions of oneof-my broadteuons corresponding in quantity of stock to the It will thus be seen that while the tenon remains in mine equally strong, the remaining thickness of the felly at each side of it is considerably increased. In Fig. VIII the increase is so much as to double the strength of the felly.

In making the mortise shown in Fig. V, two holes are bored side by side, the second one cutting into the first, and then squared by the usual mortising-machine to form the parallelogram-shaped mortise shown. The joint shown at Fig. VI may be made by boring two holes in the felly side by side and then traversing the bit, made to cut at its sides, along the mortise to clear away the middle side projections, or the latter may be cleared away by a hand chisel. The tenon to fit it would be made flat in the usual way, and it may be rounded at each edge by means of a suit-ably shaped gouge.

Fig. VII shows a modification in which two round tenons are formed side by side on the spoke by a thin hollow auger or dowel'cutter, and two round holes are bored through the felly to register therewith, thus producing an equivalent in some degree to a broad single tenon, though not possessing the whole strength of the forms shown in Figs. V, VI, and VIII.

The tenon shown in Fig. VIII may be formed by first making it round, in a hollow auger, and then. flattening the faces by aid of a tenoning machine. The mortise may first be bored, then shaped at the sides by a flat chisel and at the ends by a gouge.

Fig. XIV illustrates what I mean by the words reel-shaped, as characteristic of the form of my spoke. The plane of thef spoke and its tenon g at the inner or hub en is in the plane of the axis shown by the broken line f, while the plane of the spoke and its tenon b at the outer or felly end is at right angles thereto and coincides with the plane of the wheel. I propose to give nearly as much breadth to the spoke at the shoulder a in the plane of the wheel as to the shoulder in the plane of its axis. This may be done without waste of lumber, because the spoke-blanks when split out as usual in good work are of nearly the same thickness at both ends, and the old style reduction at the small or outer end is wasted in shavings. The common spoke, made broadest crosswise the felly, gives most shoulderbearing at the sides of the mortise,where application of pressure tends to split the felly and where the fiber of the grain may be readily pounded out; but my spoke is provided with very broad shoulders to bear across the ends of the grain,where it cannot be broken at the ends of the mortise, and with very little shoulders at the sides of the mortise, thus adding another source of strength, making it almost impossible to break the felly down over the spoke.

My spokes, having their outer tenons all in one plane .and'each tenon being so broad as to have little or no tendency to split the felly by twisting strains, have a united action in I preserving the rim of the wheel in its proper plane, so that force applied to bend any por tion of the rim is resisted by the whole wheel.

My spokes present a thin edge to the mud, and therefore pass through it without lifting and dropping so much on the rest of the wheel. Their outline is graceful in appearance and corresponds nearer to the scientific form given for the greatest strength with the least weight to cast-metal wheels, such as engine drivewheels, 8:0.

The increased cost of construction need not be one cent on a spoke, which is the merest trifle, considering the great advantage gained in strength and durability. Breadth of the inner end of the spoke in the plane of the wheels axis is not my invention; but breadth of the spoke at its outer end in the plane of the wheel is my invention independent of the shape of the inner edge.

Spokes being extensively manufactured and sold on the market as articles of commerce, this spoke is intended to take its place among the rest, and claim is hereinafter made to the spoke independently of the rest of the wheel. A spoke having broad shoulders in the plane of the wheel for the felly to rest on would obtain some of the advantages of my invention with a tenon of any shape, and if the tenon were round, like one of the tenons in Fig. XI, a spur or spud, 6, might be placed in the shoulder to prevent turning of the tenon in its mortise.

The two round tenons shown in Fig. XI or one round tenon and one or more spuds beside it in a broad-shouldered spoke would be an equivalent of my broad tenon b, and if the spoke were formed like mine a wheel so made up could not be distinguished in appearance from the genuine.

Having thus fully described my invention, what I desire to secure by Letters Patent is the following:

1. The combination of a spoke having a tenon broad in the plane of the wheel and a felly having a long mortise tofit said tenon, substantially as shown and described.

2. The reel-shaped spoke described, being broad at its outer end in the plane of the wheel and broad at its inner end in the plane of the wheels axis.

3. A wheel-spoke broad at its outer end in the plane of the wheel and thin transversely thereto and having a tenon to enter the felly.

4. A wheel-spoke provided with a tenon to enter a felly and having broad shoulders beside the tenon in the direction of the plane of the wheel for the felly to rest on and narrow shoulders at the other sides of the tenon.

5. A spoke broader at its outer end in the plane of the wheel than its thickness in a direction at right angles thereto and provided with a tenon similarly proportioned, and hav- In testimony whereof I affix my signature in ing a tenon on its inner end whose greatest presence of two witnesses.

breadth is in the direction of the wheels axis, substantially as shown and described. SAMUEL D. FORBES, 5 6. A spoke broader shouldered at its outer end in the plane of the wheel than in the di- "Witnesses:

M. O. HARLMAN,

J. JACKSON P12112012.

rection at right angles to the said plane, as described. 

